The present invention generally relates to fuel supplying apparatuses, and more particularly to a fuel supplying apparatus which is designed to prevent a fuel supplying operation from being started in a state where a valve of a fuel supplying nozzle is open after the completion of a previous fuel supplying operation without the operator being aware that the valve of the fuel supplying nozzle remains open.
Conventionally, there was a known preset type fuel supplying apparatus. According to this preset type fuel supplying apparatus, a desired quantity of fuel or a desired amount of money is preset, so that a predetermined quantity of fuel which corresponds to the preset value is supplied.
For example, a fixed type fuel supplying apparatus of the above type having the preset fuel supplying function comprises a pump and a flowmeter which are generally provided within a housing, a piping arrangement having one end thereof coupled to the pump and the flowmeter and having the other end thereof coupled to a fuel supplying hose, a fuel supplying nozzle provided at the tip end of the hose, a nozzle accommodating part which is provided on the housing so as to accommodate the fuel supplying nozzle, a switch mechanism which drives the pump when the fuel supplying nozzle is unhooked from the nozzle accommodating part, and a preset mechanism which carries out the fuel supplying operation so that a predetermined quantity of fuel which corresponds to a desired quantity of fuel or a desired amount of money which has been preset is supplied. In this fuel supplying apparatus, the desired quantity of fuel or the desired amount of money is preset in the preset mechanism, and the fuel supplying nozzle is unhooked from the nozzle accommodating part to supply the fuel to a fuel tank of a vehicle and the like. When the quantity of the fuel which is supplied to the fuel tank reaches the preset quantity, the pump is stopped from being driven so as to terminate the fuel supplying operation. The fuel supplying nozzle is then hooked back to be accommodated in the nozzle accommodating part, and in this state, the fuel supplying apparatus is ready to carry out a subsequent fuel supplying operation.
However, the fuel supplying operation which is carried out in the fixed type fuel supplying apparatus having the preset fuel supplying function described above, is different from the fuel supplying operation which is carried out in the regular type fuel supplying apparatus which depends on the operator's manual operation to open and close the valve of the fuel supplying nozzle. That is, in the preset type fuel supplying apparatus, the predetermined quantity of fuel is supplied by automatically stopping the pump from being driven when the quantity of the supplied fuel reaches the preset quantity. Thus, the operator may hook the fuel supplying nozzle in the nozzle accommodating part, without being aware that the valve of the fuel supplying nozzle still remains open. As a result, when the open fuel supplying nozzle is unhooked from the accommodating part so as to start a subsequent fuel supplying operation, the switch mechanism will operate immediately and drive the pump. Therefore, there is a danger in that the fuel may be supplied through the fuel supplying nozzle before the fuel supplying nozzle is inserted into a fuel supplying opening in the fuel tank of the vehicle.
On the other hand, similar problems occur in the case of a hanging type fuel supplying apparatus having the preset fuel supplying function. In the hanging type fuel supplying apparatus, the fuel supplying nozzle can assume a waiting position which does not interfere with a vehicle which enters and leaves a fuel supplying station, and a fuel supplying position which is suited for performing the fuel supplying operation with respect to the vehicle. However, after the preset fuel supplying operation is completed, the operator may return the fuel supplying nozzle from the fuel supplying position to the waiting position without being aware that the valve of the fuel supplying nozzle still remains open. As a result, when the fuel supplying nozzle is moved from the waiting position to the fuel supplying position so as to start the subsequent fuel supplying operation, a switch mechanism which drives the pump when the fuel supplying nozzle is moved to the fuel supplying position will operate immediately and drive the pump. Therefore, there is a danger in that the fuel may be supplied through the fuel supplying nozzle before the fuel supplying nozzle is inverted into the fuel supplying opening in the fuel tank of the vehicle.
Further, similar problems occur in the case of a fuel supplying apparatus having a function of controlling the supply of fuel to an integral quantity. In such a fuel supplying apparatus, when an integral fuel supply instruction switch is manipulated during the fuel supplying operation so as to perform an integral quantity fuel supplying operation, the driving of the pump is controlled so that the fuel supplying operation is completed when the quantity of supplied fuel is exactly an integral quantity. Hence, after the integral fuel supplying operation is completed, when the operator hooks the fuel supplying nozzle onto the accommodating part in the case of the fixed type fuel supplying apparatus or returns the fuel supplying nozzle to the waiting position in the case of the hanging type fuel supplying apparatus without being aware that the valve of the fuel supplying nozzle still remains open, there is a danger in that the fuel may be supplied through the fuel supplying nozzle before the fuel supplying nozzle is inserted into the fuel supplying opening in the fuel tank of the vehicle.
Accordingly, there is an apparatus which is designed so that the pump will not be driven unless it is checked before the fuel supplying operation is started whether or not the valve of the fuel supplying nozzle is open. However, in this apparatus, the state of the valve of the fuel supplying nozzle has to be checked every time a fuel supplying operation is carried out, and there is a disadvantage in that such checking of the state of the valve of the fuel supplying nozzle is troublesome to perform.